Detonation burning of anthracite and lignite particles in a flow-type radial combustor

Abstract

Regimes of continuous spin detonation of anthracite and lignite particles in an air flow in a radial vortex combustor 500 mm in diameter with a constant (along the radius) cross-sectional area are studied. Ground coal with a particle size of 1–12 μm is used. For transporting coal into the combustor and promoting the chemical reaction on the surface of solid particles, hydrogen or syngas is added in the ratio CO/H₂ = 1/1, 1/2, or 1/3. Continuous spin detonation of two-phase mixtures of fine anthracite and lignite particles and air with addition of hydrogen up to 4% of the coal consumption rate is obtained for the first time. The amount of syngas added to coal increases with decreasing fraction of hydrogen in the syngas: 14, 21, and 27% for anthracite and 11, 20, and 29% for lignite at CO/H₂ = 1/3, 1/2, and 1/1, respectively. The structure of detonation waves and the flow in their vicinity are not principally different from those observed previously for long-flame bituminous coal and charcoal. Higher detonation velocities are observed for more energy-intensive coal (anthracite). A higher pressure is obtained near the cylindrical wall of the combustor in cold runs as compared to detonation in the case with identical flow rates of the coal–air mixtures.